1. Field of the Invention
This invention lies in the field of data acquisition systems in general. More particularly, this invention relates to acquisition systems that have a high plurality of signal sources, such as geophones, and which utilize array terminals for gathering analog signals from each of a plurality of signal sources.
Still more particularly, this invention relates to a system for seismic operations for gathering geophone signals, converting them in array terminals to 1-bit digital signals, and transporting these signals as trains of 1-bit pulses to a central recording station.
2. Description of the Prior Art
In the prior art there are a number of patents which describe a wide variety of data acquisition systems, which use a common two-conductor digital signal line. In these systems each sensor or source of analog signals comprises a separate entity with power supply, amplifier means, digitizing means, storage means, and transmitting means, to apply on demand a digital word to be transmitted down the two-conductor line to the recording station.
In a series of patents recently issued, there is described a type of acquisition system in which a great number of analog signal sources are provided in groups, each group being connected into a separate array terminal, where each of these signals are amplified, digitized to 1 bit, and stored, and then transmitted down a two-conductor line to the next downline array terminal, and so on, into the central storage means.
This invention is an improvement on the latter type of acquisition system, and provides an improved method of cabling between the array terminals, and improved circuitry in the array terminals for amplifying and digitizing the analog signals and for relaying the digital signals from upline array terminals, and so on.